This recession will not last forever, even the MOD know this and the last thing they want is a mass exodus whilst trying to meet stated commitments.
How long will it last?
I will be surprised to see any form of 'growth' (personally I see this as GDP greater than inflation by at least 1%) for the next decade. That is a LONG time to wait for all those defence projects we need. The only thing I can see changing in the medium term are our overseas commitments. UK defence force here we come...